I've not done this in a LOOONG time, but the IDP 8200 should have the web-based configuration tool "ACM" which should allow you to tell it where to phone-home to talk to its NSM.

Another suggestion would be to ensure your IDP can ping the NSM box, and the NSM box can ping your IDP.

Finally, if you turned off or filtered SSH access using the ACM, you might want to un-do that, as NSM uses SSH (initially) to take control of your IDP. Once it has it configured for management, it uses NSM BeeHive instead.

As a matter of style, I'd also recommend you configure your IDP to be managed out-of-band (OOB) using its management interface, and using the inspection interfaces in "Stealth" mode (un-IP'd) and the IDP in "Transparent" mode. The actual implementation is up to how your network is set up, of course, but this is my favorite method of IDP deployment.